[Bazooka_Joe]

[quote="Neo Nazi Hitler":63bd0]I thought it was every 7 years.

All your cells in your body replace themselves every 7 years.

Well it takes 7 years for ALL of the cells to be replaced. and than after so many regenerations the telomeres wear down and that's where aging kicks in.[/quote:63bd0]

Yes, every 7 years, your entire body replaces all of your old cells. This is generally why you don't take a new photo for a drivers lisence for every 8 years, because unless you gain/lose alot of weight, you really won't change appearance that much.